Printing plate and method of making the same



'C. G. HAYES Oct. 13, 1931.

PRINTING PLATE AND METHOD OF MAKING THE SAME Filed April 5, 1930 surface I stain oct. 1 1 3 1 7 I @CHARLES e. HAYES, or cnioaeo, ILLmoIsAssroNpa or CHICAGO, ILLINOIS,

5 PRINTING PLATE'AND METHOQ' QiFill/f Application Theinvention relates to printing plates print n having screenformed or half-tone surfaces, and seeks to providejan improve plate of this sort" and a simple, convenient method of forming the same.

The usual half-tone platehas its print ng all in a common lights, dark tones, and tones formed by varying the size of the screen dots or figures. VVithsuch plates, and

', particularly whenlhigh lights form the edge portions of itsprinting blurred lines are apt to be printing operation 'tions, andsuc formed 1n the by the edges oredgep'orproperly corrected by the' 1 u 1" k ready methods. w

' V is provided formed by high lights. r with the improvement, the

' with a suitable formed printing surface.

its under s1de 1501113 away or- The present invention seeks to provide a plate having a half-tone or v screen-formed printing surface which will not blur 1n the printing operation along theedge of its prlnt-v ing surface, andto avoid this defect a in which its metal body 1s slightly depressed along the edges of its printlng surface, or along such edge portions as are In accordance plate is first made in any usual way by electrotyping or other process which-providesa half-tone'or screen- Then the metal of the plate on v v grooved beneath the edges of the printing surface, or beneath such portions of'the edges as' are formed by or border upon h1gh lights, and such edges or edge'portions are then slightly depressed by applying pressure to the upper surfaceof the plate along a line closely adjacent, but outside, the edge por- The foregoing features of the inventionare hereinafter more fully set forth, andone embodiment ofthe improved plate is illustrated in'the accompanying drawings, andthe invention is particularly defined in the appended claims. Y

In the drawings: v F I Fig. Lisa plan view of an embodiment of the improved plate, and v 1 i screen-formed printing surfaces band 0. customary, the: plate outside of the printingisurfaces IlS; g. .cut away. a

plane with a high intermediate surface, heavy ingf operation, defects are not readily and plate '12 in Fig.

or edge portion is blunt tool ,or tamping', device ro orrIoAGo "cannon. conf rms, a A oonroaarrron-orrrmnors 7 Qis. a cross section onan enlarged scale} taken. onthe line-22 of'Fig. 1.

The'plate'a' is formed as usualtof suitable t e metal by electrotyping or other suitable 55.15 a

process, -and is provided with half-toneXr the metal at the'upper surface of;

In the particular embodiment ,shown, right-hand:edgeylOiofthe printing surface cis formed by orborders on a under side and beneath: the edge 10 ifs first.- cut away. to

groove extends laterally asshownone oppoe site sides of the edge 10.3 i ii i 1; applied to the upper, surfaceofthe plate along; and closelyv outside of the printing surface whereby the: metal of the plate above'the grooveis slight- .Then" pressure. is

adjacent the edge;10,-"but' ly depressed, suclr depression in somewhat exaggerated} Any suitable means could be employed for slightly depressing the above the groove 11. For-example, a blunt tamping tool'could be used to apply pres-- I i sure along a line indicated by the numeral 2; or. a piece'of hard wood could beplaced on the"plate against the edge 10 high'lightfiif L Toavoid blurringby the edge 10 inthe printthe metali of--theplate on its, 1

as: form a shallow grooverll.

bemgmdicated 1 form in Fig. 2.

metal of the plate sea of the raised printing surface and then struck lightly with a hammer. r I The improved pressure to the printingsurface itself or in anyway marrmg it will not blur in the printing; operation. Also, the method is such that aha'lf-tone plate can be very readily and properly corrected. to avoid such blurring. I

Changes forth without departure from the scopeof: the invention as defined. infthe appended I claim as'my invention:' v

' i 1. A printing plate provided with a halftone printing surf in its lower facebeneath a portion of the 1 edge" of the printing surface,

ace and having a groove themetal of method" avoids applying i" Q i '85; such surface, but its edges slightly depressed so that j may be made in the details set" the plate, along the edge of the printing surface and above the groove being depressed, substantially as described.

2. The method of correcting a printing plate which consists in grooving the under surface of the plate beneath an edge portion of its printing surface, and then depressing the metal of the plate above the groove by the application of pressure to the upper face of the plate along and adjacent the edge portion of the printing surface but outside of such surface, substantially as described.

3. A printing plate having a groove formed in its flat lower face inside the edge of the plateand extending in part beneath and in part outside an edge portion of the printing surface, the metal of the plate above the groove being depressed, substantially as described.

4. The method of treating a printing plate which comprises forming a groove in its flat lower face inside the edge of the plate, and disposed in part beneath and in part outside an edge the plate, the plate described.

5. The method of treating a printing plate which comprises cutting a groove in its fiat lower face disposed inside of the edge of the plate and beneath at least a portion of and then depressing the metal of above the groove, substantially as the edge of the printing surface of the plate, and then depressing the metal of the plate above the groove by the application of pressure along a line closely adjacent, but outside, the edge portion of the printing surface, substantially as described.

' CHARLES G. HAYES.

portion of the printing surface of 

